1221566677 has 16 divisors (see below), whose sum is σ = 1304087040. Its totient is φ = 1140976368.

The previous prime is 1221566657. The next prime is 1221566711. The reversal of 1221566677 is 7766651221.

It is a cyclic number.

It is not a de Polignac number, because 1221566677 - 2¹¹ = 1221564629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221566617) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 460168 + ... + 462814.

It is an arithmetic number, because the mean of its divisors is an integer number (81505440).

Almost surely, 2^1221566677 is an apocalyptic number.

It is an amenable number.

1221566677 is a deficient number, since it is larger than the sum of its proper divisors (82520363).

1221566677 is a wasteful number, since it uses less digits than its factorization.

1221566677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3000.

The product of its digits is 211680, while the sum is 43.

The square root of 1221566677 is about 34950.9181138350. The cubic root of 1221566677 is about 1068.9869227399.

The spelling of 1221566677 in words is "one billion, two hundred twenty-one million, five hundred sixty-six thousand, six hundred seventy-seven".